Fire-resistant article, method of making, and impregnant therefor



UNITED STATES Patented Apr. 3, 1951 ENT. orrc FIRE-RESISTANT ARTICLE, METHOD OF MAKING, AND IMPREGNANT THEREFOR Morris J. Sostmann and Irwin L. Phillips, Philadelphia, Pa., assignors to Philadelphia Textile Finishers, Inc., Norristown, Pa., a corporation of Delaware No Drawing.

'materials to decrease their combustibility, or

what is the same thing, to increase their fire resistance. The compositions, for want of a better term will be referred to as fire-proofing compositions and the active ingredients will be referred to 'as' fire-proofing ingredients.

In another aspect, the invention concerns itself Application October 13, 1945, Serial No. 622,234

with methods for making fire-proofing compositions.

In another aspect, the invention concerns itself with methods for treating combustible materials I to render them fire-resistant. For convenience of reference, such methods will be termed fireproofing methods.

In a further aspect, the invention concerns itself with a product resulting from treating normally combustible materials with the fireproofing compositions of the invention. Such products will be referred to as fire-resistant products", the words fire-resistant meaning vegetable or synthetic origin in various forms,

suchas textile fabrics of cotton, linen, "wool, mrqninr .q t 9r m e v here paper n pulp, --.-web, sheet or lami ated form, and wood in the k q m q e es articles- The fire-proofing compositions of the invention aqueous solvent.

b that the product has an increased resistance 1 I either to fiaming'or to glowing or to both types i i of combustion.

The invention 'isfapplicable generally for the treatment of combustible material of animal,

acetic anhydride for three hours.

making the antimony oxide reaction product:

One part by weight of commercial antimony trioxide is refluxed with two parts by weight of Almost all of the antimony oxide dissolves, producing a cloudy tan solution. When'cool, the mixture consists of about two-thirds by volume of plate-like crystals and one-third of a clear-brown liquid.

The'mixture may be separated by filtration into.

a large mass of crystals and a clear bright brownred liquid. The crystals are apparently antimonyl acetate, and the clear filtrate is apparently a saturated solution of the same compound,

The filtrate may be used to impregnate cloth to render it fire-resistant. It is only necessary to dry the impregnated cloth, but if desired, the-cloth may be washed with water until free of acetic acid. The washing with water serves to hydrolyze" the antimonyl acetate, an antimony compound being precipitated in situ. If the impregnatedcloth is dried without washing out the acetic acid, hy-

drolysis occurs during use or subsequent laundering. In any event, the resultant cloth'has a substantiallyv increased resistance to fire.

The crystals of antimonyl acetate may also be used to treat combustible materials. For this purpose, they may be admixed .or dissolved in a non- Practically any solvent for acetic anhydride may be used; The preferred solvents are organic carboxylic acids such as, e. g.

formic, aceticf' halogenated acetic, preferably mono-chloracetic, phenylacetic, and lactic acid. Othersuitable solvents are the aromatic hydrocarbons such as benzol,-toluol, xylol, coal tar naphthas, and hydrogenated. solvent naphthas such as..Solvesso.

consist essentially of the reaction products of but'yric anhydride, benzoic anhydride, camphoric :antimony'trioxide with the anhydride of an organiccarboxylic acid such as acetic anhydride, the chloroacetic anhydrides,.propionic anhydride,

anhydride, and naphthalic anhydride'or with one or more of said anhydrides. The composition is probably an antimonyl compound, e. g. in the case of acetic anhydride it is very likel antimonyl acetate, CHsCOzSbO.

The invention will be described with particular reference to the reaction product of antimony oxide with acetic anhydride.

The following is an illustrative method for The material to be; rendered fire= res istant is impregnated with 'thejsolution, and the "solvent thendriven off, leavingjtheantimonyl compound in the interstices.v "If thought necessaryor. desirable, the antimonyl compound may be hydrolyzed by washing the impregnated material.

. In the case of a water-miscible solvent, it is-not necessary to drive off the solvent before washing with water.

h It is not necessaryto separate'the crystals from the filtrate before treating combustible materials. The mixture of crystals and brown liquidmay be mixed with a solvent for the crystals, and the resulting solution used as a fire-proofing composition. Any of the previously mentioned solvents may be used, but acetic acid is preferred. The impregnated combustible material may be treated in any of the ways previously described.

In the preferred embodiment of the invention,

the antimony trioxide and acetic anhydride in the stated proportions are refluxed together until the oxide is completely dissolved. The result is a solution in acetic anhydride of what is apparently. antimonyl. acetate. This. solution .may

be applied to cloth or other' combustiblematerial in exactly the same manner previously described. Instead of or in addition to acetic anhydride,

any of the other anhydrides mentioned may be used either separately or in admixture with one.

another. At this point, it' is'to be notedth'at in the case of solid anhydrides such as-chloracetic,

benzoic and camphoric, the-antimony oxide may be simply mixed with theflanhydride in molten form, and the product then dissolved in the sol vent. Antimony oxide is readily soluble in the molten anhydrides above mentioned.

The antimony trioxide-anhydride reaction product may be compounded with .'other' fireproofing materials, Ssuch as for instance am- "and-acid solvent specified in the examp e. Since 4 For illustrative purposes, the invention has been described with particular reference to the treatment of textile fabrics such as cotton duck for the purpose of increasing their resistance to .fire.- It is to be understood, however, that the claims are not to be. restricted to this specific application. For, as has been indicated, the invention is applicable to the treatment of combustible materials generally. Furthermore, the invention-is not-to be restricted to the anhydride .thecther anhydrides, and solvents mentioned in the disclosure may be used with substantially the Lsame resultsi- Moreover, the fire-proofing treatment ofr'the' invention may be combined with various other treatments, e; g. waterproofing 'a'nd/or mildew-proofing. The additional treatments may be combined in one operation with therfire-proofing, or applied in preliminary or .nronium compounds, aromatic phosphates, 'vis- .couszrchlorinated hydrocarbons such as, chlo- 'rinated. rubber; chlorinatedparafiin; chlorinated .naphthalene;-.etc. ---Chlorinated*paraffins have been:found'particularlysuitable, especially those containingimore" than about 40 chlorine .The

subsequent operations. As an example, it may be stated thatfibrousmaterial; impregnated with antimonyl acetate or with hydrolyzedsantimonyl .acetate may beicoated-"with a. filmaof chlorlnated ichlorinated'parafiins, in- -addition to being 'fireproofingmaterials themselves; are vfilm formers, 'and serve to bindathe precipitated antimony oxide :to': the 1 fabric; Other ingredients may also "ingiagentsletc.

The -following'iis giver-1 by 'way of: example; the

.amountsrbeing 'byiwe'ight:

Parts I zz Antimonystrioxide J..- a 100 'Aceti'c anhydride 2200 Chlorinated-paraflin (f42 %)d 122.5 l "-Chl'orinatediparafiinC7 0%) 27.5 .PAcetic 1.'acid 1 800* .Theantimony trioxide and acetic "anhydride I hy'drolysislwillt occur gradually duringuse of. the

. impregnated cloth, or during laundering.

I The final. product has its original color, li'and, fe'el, flexibility, and in. addition showsexcellent -resistance to flame; and to char or afterglow. "l The fire resistance isfretained'. after prolonged t exposure to water and weathering." If'it is desired to change the color, a suitablefdye or. pigment may be added toithe composition, 'or'the Q- b'e added,Iasipigments, extenders; mildew-proofhydrocarbon such as chlorinatedrubber .or iparaffin, synthetic resins such as vinyl acetate-,--copolymerized. vinyl chloride: and"ayinyl.:-sacetate.

melamine resins, chlorinated ,polystyrene', etc.

We claim: 1. -A.- composition' for rendering combustible materials.fire-resistant, said compositionwl'ieing theh'product obtained by.refluxing onerpart by weight of antimony trioxide.with=.twoparts by weight-of acetic:anhydrideuntil-the oxideiislcomwpletely. dissolved.

. 2. IA: method or rendering :1 combustiblet.-"material fire-resistant, which consists in:;impregnating said. material with: thencompositionldefined .in claim 1.

mally combustible; base .impregnatedl iwith the .icompositionedefined.in claim 1.

3. A fire-resistant material consistingzof: amor- MORRIS. JESOSTMANN. IRWIN IJL':..PHILI$IPS.

" i J REFERENCES CITED The following references are of. record inwthe file of. this patent:

a ..''1 UNITED STATES PATENTS Number Name "Date 1,451,313 Arent 'li Apr. 10;."1923 1,867,658 Dreyfus '.'.i July. 19; 1932 2,231,784 Mohr May 15;1942 2,299,612 FcClaytoniet a1. iOct'. 20,1942

. .FOREIGN PATENTS Number Country .".:-"'Date 8,509 GreatBritain "122,621 Germany 846,522 France '-'June 12?)1939 fire-resistant product dyed or; pigmented in a suitable manner.

.. I OTHER".REFERENCES ;.Christiansen: .Organic- Derivatives otzieAntimony,:.publ. by the. ChemicaLCatalogxGo. of N. Y'., 1925,.pp."74.-80, I98 and 199.

: ';.The: Fireproofing of'Textiles; byzilextilea-Re- 1 search. Institution, (1943) ,:page 6. 

1. A COMPOSITION FOR RENDERING COMBUSTIBLE MATERIALS FIRE-RESISTANT, SAID COMPOSITION BEING THE PRODUCT OBTAINED BY REFLUXING ONE PART BY WEIGHT OF ANTIMONY TRIOXIDE WITH TWO PARTS BY WEIGHT OF ACETIC ANHYDRIDE UNTIL THE OXIDE IS COMPLETELY DISSOLVED. 